OCTOBER 2021
FACT SHEET
Law of the Colorado River The Colorado River rises in the Rocky Mountains and flows, along with its tributaries, southwest, covering nearly 250,000 square miles through Wyoming, Colorado, New Mexico, Utah, Arizona, Nevada, and California before entering the Mexican states of Sonora and Baja California and emptying into the Gulf of California. It provides drinking water for about 40 million people, including those in the major metropolitan areas of Denver, Phoenix, Tucson, Las Vegas, Los Angeles, and San Diego. More than 70% of the river’s water is used to irrigate about 4.5 million acres of farmland, generating some 15% of the United States’ food.
Colorado River Basin Watershed Watershed
THE LAW OF THE RIVER Use of the Colorado River is governed by the 1922 Colorado River Compact and a series of new, layered agreements known collectively as the “Law of the River.” These include the 1944 U.S.Mexico Water Treaty, the 1948 Upper Colorado River Basin Compact, various congressional acts, and other legal settlements and agreements that govern the river’s operations, infrastructure and water allocations. Since 2000, a multidecadal drought has restricted
NM
60 The Law of the River and Lake Powell and Lake Mead Combined Storage
Reservoir storage in millions of acre-feet
Combined maximum capacity
50
2019
1968
Colorado River Basin Project Act
40
1948
Upper Colorado River Basin Compact 1944
30
2007
Drought Contingency Plan and Binational Water Scarcity Contingency Plan
Interim Guidelines for Lower Basin Shortages and Coordinated Operations for Lakes Powell and Mead
1956
Colorado River Storage Project Act
U.S.-Mexico Water Treaty
LAKE POWELL STORAGE
20
10
LAKE MEAD STORAGE 1922
Colorado River Compact
1928
0 1937
Boulder Canyon Project Act
1947
1957
1967
1977
1987
1997
2007
2017